The Cardinal Manifestations of Traumatic Brain Injury
This chapter and the next set out a method of eliciting as complete and well-rounded a picture as possible of the client's behavior. To do so, it is necessary to have a clear view of the behavioral changes that follow most traumatic brain injuries, and a method of eliciting descriptions of these changes. These matters are dealt with in sequence in this chapter and the next, which are both about the diagnosis that comes before testing. This "before" has a twofold primacy: First, behavior in the real world has precedence over behavior in the test room, and second, it is the client's behavior that determines the selection of tests, their prognostic interpretation, and the structure of the neuropsychological report (chap. 11).
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Worldwide, diffuse traumatic brain injuries are the most commonly encountered type of brain damage. These are caused by the application of violent accelerative or decelerative forces to the head: Accelerative forces arise in pedestrian motor vehicle accidents and from blows to the head, and decelerative forces occur during heavy falls, and for the occupants of motor vehicles involved in accidents. In the United States, traffic accidents account for between 60% and 80% of all brain injuries ( Romer et al., 1995). In Bangalore, India, 62% of brain injuries are caused by traffic accidents ( Channabasavanna, Gururaj, Das, & Kaliaperumal, 1994). In South Africa, traffic accidents cause 73% of all brain injuries among White males, but cause only 30% of such injuries among Black South Africans.